Organic EL device

ABSTRACT

An organic EL device having a light emitting element including a first electrode ( 2 ), a second electrode ( 4 ) of transparent conductive film, and a light emitting organic material layer ( 9 ) formed between said first electrode ( 2 ) and said second electrode ( 4 ), wherein said transparent conductive film is made of a metal oxide deficient in oxygen as compared with stoichiometric composition. Since the transparent conductive film ( 4 ) directly in contact with the light emitting organic material layer ( 9 ) over a wide area is made of the metal oxide deficient in oxygen as compared with stoichiometric composition, the transparent conductive film can absorb moisture and oxygen which may possibly absorbed by the light emitting organic material layer so that the light emitting organic material layer is prevented from deteriorating, and the long emission lifetime of the element can be ensured.

TECHNICAL FIELD

The present invention relates to an organic EL device having a lightemitting element which includes a light emitting organic material layersandwiched between two electrodes including a transparent conductivefilm electrode, and more particularly to an organic EL device which issuitable for use with a display device.

BACKGROUND ART

One type of the display devices employing self-luminescence elementsutilizes electroluminescence elements (EL elements). The EL element isdivided into an organic EL element having a light emitting layer made ofan organic material and an inorganic EL element having a light emittinglayer made of an inorganic material.

The organic EL element includes an anode, a cathode, and an organic ELlayer which is sandwiched between these two types of anode and cathodeelectrodes and which is made of thin film of an organic light emissivecompound. Applying a voltage between the anode and the cathode causesthe anode and the cathode to inject holes and electrons into the organicEL layers respectively, for recombination. The energy produced thenexcites the molecules of the organic light emissive compoundconstituting the organic EL layer. A light emitting phenomenon isprovided in the process of such excited molecules being deactivated intotheir ground state. The organic EL element is a light emitting elementwhich utilizes this light emitting phenomenon.

The organic EL layer includes at least an organic layer called a lightemitting layer in which holes and electrons are recombined to emitlight. When necessary, the organic EL layer has a single-layer structureor a multi-layered structure that includes one of or both an organiclayer called a hole transport layer which allows holes to be readilyinjected therein but electrons to hardly travel therethrough and anorganic layer called an electron transport layer which allows electronsto be readily injected therein but holes to hardly travel therethrough.

In recent years, the organic EL element is actively being studied andbrought to practical use. This element has a basic structure in which ahole injection material such as triphenyldiamine (TPD) is evaporated toform a thin film on a transparent electrode (a hole injection electrodeor an anode) such as indium tin oxide (ITO), and a phosphor such as analuminum quinolinol complex (Alq₃) is then deposited as a light emittinglayer, with a metal electrode (an electron injection electrode or acathode) having a low work function such as AgMg being subsequentlyformed. Attention is now focused on this element because the elementprovides as very high a brightness as several hundreds to several tensof thousands of cd/m² at a voltage of about 10V and thus can be used asan illumination lamp, a light source, or a display for OA devices, homeelectric appliances, automobiles, two-wheeled vehicles, airoraft, and soon.

For example, such an organic EL element is configured such that anorganic layer such as a light emitting layer is sandwiched between ascan (common line) electrode serving as an electron injection electrodeand a data (segment line) electrode serving as a hole injectionelectrode (transparent electrode), and is formed on a transparent(glass) substrate. On the other hand, the display is largely dividedinto two types: a matrix display that allows the light emitting elementsdisposed in a matrix to emit light dot by dot using the scan electrodesand data electrodes arranged in the horizontal and vertical directionsin order to display information such as an image or character as acollection of these dots (pixels), and a segment display that allows anindicator present independently as having a predetermined shape and sizeto be displayed.

For the segment type display, it is possible to employ a static drivesystem by which each indictor is displayed separately independently.However, for the matrix display, normally employed is a dynamic drivesystem which allows each scan line and data line to be driven in timedivision manner.

The light emitting element constituting the light emitting portion ofthe organic EL element is divided into the following types: a substratesurface emission type that uses the structure of transparentsubstrate/transparent electrode/light emitting layer/metal electrodeallowing light generated in the light emitting layer to be emittedthrough the transparent electrode and the transparent substrate, and afilm surface emission type that uses the structure of substrate/metalelectrode/light emitting layer/transparent electrode allowing lightgenerated in the light emitting layer to be emitted through thetransparent electrode from the film surface side opposite to thesubstrate surface. The element of the substrate surface emission type isdescribed, for example, in Appl. Phys. Lett., 51, 913-915 (1987), whilethe element of the film surface emission type is described, for example,in Appl. Phys. Lett., 65, 2636-2638 (1994).

An organic fluorescent solid body serving as a material of the lightemitting layer in the organic EL element is quite susceptible todeterioration from moisture, oxygen or the like when exposed thereto. Anelectrode disposed directly or via the electron transport layer on thelight emitting layer is also quite susceptible to deterioration incharacteristics from oxidation. This causes a prior art organic ELelement to suddenly deteriorate in its emission characteristics when itis driven in the air. In particular, the presence of oxygen or moisturearound the element raises a problem of accelerating oxidation therebycausing the organic material to be altered in quality, the film to bepeeled off, and a dark spot (non-light emitting portion) to grow,resulting in loss of lifetime. Accordingly, to obtain a practicalorganic EL element or organic EL device, it is necessary to devise thestructure of the element to prevent the intrusion of moisture or oxygeninto the light emitting layer and the oxidation of its oppositeelectrode.

To solve the aforementioned problems, it is suggested to seal theorganic EL element to prevent it from being exposed to the air. Forexample, Japanese Patent Laid-Open Publication. No. Hei 5-182759discloses that an organic EL element is covered with and thereby sealedin a photocurable resin layer resistant to moisture and a substratesecured onto that layer and having a reduced permeability to moisture.On the other hand, Japanese Patent Laid-Open Publication No. Hei 5-41281discloses that an El element is sealed in an inert liquid having adehydrating agent such as synthetic Zeolite contained in a fluorocarbonoil. On the other hand, Japanese Patent No. 2800813 discloses a methodfor providing an organic EL element with a fluorine-based polymerprotective layer, disposing outside that layer a sealing portion havinga cap structure, and filling the sealing portion with an inert m diumfor encapsulation.

It has also been suggested that deterioration is prevented by capturingmoisture. For example, Japanese Patent Laid-Open Publication No. Hei3-4481 discloses that an organic EL element is coated with a moisturecapturing layer. In addition, Japanese Patent Laid-Open Publication No.2000-30871 describes that a moisture capturing material is contained inan insulating layer that fills between the transparent electrodesarranged in a matrix.

However, the application of only the sealing techniques was notsufficient to completely remove the moisture and oxygen present aroundthe element, thereby making it difficult to ensure a sufficiently longemission lifetime. Furthermore, since usage of the prior art sealing mayresult in an increase in thickness of the display device by the amountof a sealing member, it is desirable to ensure a light emission sustaintime without using the sealing, if possible.

Still furthermore, even the structure provided with a moisture capturinglayer raises a problem of causing an increase in thickness of a displaydevice by the amount of the layer. In the methods employing the priorart moisture capturing layer and the moisture capturing material, sincethe moisture capturing layer or the moisture capturing material is notin direct and entir contact with the organic film, it is difficult toprovid a sufficient moisture capturing effect to the organic film.

DISCLOSURE OF THE INVENTION

The present invention is intended to solve the aforementioned prior artproblems. It is therefore an object of the invention to provide anorganic EL device which can ensure an elongated light emission sustaintime with encapsulation and which also can ensure a practical lightemission sustain time even without encapsulation.

To achieve the aforementioned object, the present invention provides anorganic EL device having a light emitting element including: a firstelectrode; a second electrode of transparent conductive film; and alight emitting organic material layer formed between the first electrodeand the second electrode. The transparent conductive film is made of ametal oxide deficient in oxygen as compared with stoichiometriccomposition.

Furthermore, preferably, the transparent conductive film is made of ITOhaving a composition of In_(2-x)Sn_(x)O_(3-y) (where 0<x<1 and0.05≦y≦0.2). Furthermore, preferably, the first electrode is made of anyone of MgAg, Al, and LiAl.

According to the organic EL device of the present invention, thetransparent conductive film directly contacting the light emittingorganic material layer over a wide area is made of a metal oxidedeficient in oxygen as compared with stoichiometric composition. Thepresent invention thus allows the transparent conductive film to absorbmoisture and oxygen that may be possibly absorbed by the light emittingorganic material layer, thereby making it possible to preventdeterioration of the light emitting organic material layer and ensure anelongated emission lifetime of the element.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1( a) to 1(h) are sectional views each showing a multilayerstructure of a light emitting element according to the presentinvention;

FIGS. 2( a) to 2(h) are sectional views each showing a multilayerstructure of a light emitting element according to the presentinvention;

FIGS. 3( a) to 3(h) are sectional views each showing a multilayerstructure of a light emitting element according to the presentinvention;

FIGS. 4( a) to 4(h) are sectional views each showing a multilayerstructure of a light emitting element according to the presentinvention;

FIGS. 5( a) to 5(h) are sectional views each showing a multilayerstructure of a light emitting element according to the presentinvention;

FIGS. 6( a) to 6(h) are sectional views each showing a multilayerstructure of a light emitting element according to the presentinvention:

FIGS. 7( a) to 7(h) are sectional views each showing a multilayerstructure of a light emitting element according to the presentinvention;

FIGS. 8( a) to 8(h) are sectional views each showing a multilayerstructure of a light emitting element according to the presentinvention;

FIGS. 9( a) and 9(b) are sectional and plan views each showing anexemplary light emitting element according to the present invention,FIG. 9( c) being a sectional view showing a modified example of FIG. 9(a);

FIGS. 10( a) and 10(b) are sectional and plan views each showing anotherexemplary light emitting element according to the present invention,FIG. 10( c) being a sectional view showing a modified example of FIG.10( a);

FIGS. 11( a) and 11(b) are sectional and plan views each showing stillanother exemplary light emitting element according to the presentinvention, FIG. 11( c) being a sectional view showing a modified exampleof FIG. 11( a);

FIGS. 12( a) and 12(b) are sectional and plan views each showing stillanother exemplary light emitting element according to the presentinvention, FIG. 12( c) being a sectional view showing a modified exampleof FIG. 12( a);

FIGS. 13( a) and 13(b) are sectional and plan views each showing stillanother exemplary light emitting element according to the presentinvention, FIG. 13( c) being a sectional view showing a modified exampleof FIG. 13( a);

FIGS. 14( a) and 14(b) are sectional and plan views each showing stillanother exemplary light emitting element according to the presentinvention, FIG. 14( c) being a sectional view showing a modified exampleof FIG. 14( a);

FIGS. 15( a) and 15(b) are sectional and plan views each showing anexemplary arrangement of light emitting elements available to an organicEL device according to the present invention;

FIGS. 16( a) and 16(b) are sectional and plan views each showing anotherexemplary arrangement of light emitting elements available to an organicEL device according to the present invention;

FIGS. 17( a) and 17(b) are sectional and plan views each showing stillanother exemplary arrangement of light emitting elements available to anorganic EL device according to the present invention;

FIGS. 18( a) and 18(b) are sectional and plan views each showing anexemplary structure of a light emitting element in an organic EL deviceaccording to the present invention, FIG. 18( c) being a sectional viewshowing a modified example of FIG. 18( a);

FIGS. 19( a) and 19(b) are sectional and plan views each showing anotherexemplary structure of a light emitting element in an organic EL deviceaccording to the present invention, FIG. 18( c) being a sectional viewshowing a modified example of FIG. 18( a);

FIGS. 20( a) and 20(b) are sectional and plan views each showing stillanother exemplary structure of a light emitting element in an organic ELdevice according to the present invention, FIG. 20( c) being a sectionalview showing a modified example of FIG. 20( a);

FIGS. 21( a) and 21(b) are sectional and plan views each showing stillanother exemplary structure of a light emitting element in an organic ELdevice according to the present invention, FIG. 21( c) being a sectionalview showing a modified example of FIG. 21( a);

FIGS. 22( a) and 22(b) are sectional and plan views each showing stillanother exemplary structure of a light emitting element in an organic ELdevice according to the present invention, FIG. 22( c) being a sectionalview showing a modified example of FIG. 22( a);

FIGS. 23( a) and 23(b) are sectional and plan views each showing stillanother exemplary structure of a light emitting element in an organic ELdevice according to the present invention, FIG. 23( c) being a sectionalview showing a modified example of FIG. 23( a);

FIGS. 24( a) and 24(b) are sectional and plan views each showing stillanother exemplary structure of a light emitting element in an organic ELdevice according to the present invention, FIG. 24( c) being a sectionalview showing a modified example of FIG. 24( a);

FIGS. 25( a) and 25(b) are sectional and plan views each showing stillanother exemplary structure of a light emitting element in an organic ELdevice according to the present invention, FIG. 25( c) being a sectionalview showing a modified example of FIG. 25( a);

FIGS. 26( a) and 26(b) are sectional and plan views each showing anexemplary arrangement of light emitting elements in an organic EL deviceaccording to the present invention;

FIGS. 27( a) and 27(b) are sectional and plan views each showing anotherexemplary arrangement of light emitting elements in an organic EL deviceaccording to the present invention:

FIGS. 28( a) and 28(b) are sectional and plan views each showing stillanother exemplary arrangement of light emitting elements in an organicEL device according to the present invention;

FIGS. 29( a) and 29(b) are sectional and plan views each showing stillanother exemplary arrangement of light emitting elements in an organicEL device according to the present invention;

FIG. 30( a) is a schematic sectional view showing an exemplary structureof a light emitting element with a drive portion in an organic EL deviceaccording to the present invention, FIG. 30( b) being a plan viewshowing a plurality of light emitting elements each having the driveportion of the structure and disposed in the horizontal and verticaldirections:

FIG. 31 is a plan view showing an exemplary relation between a lightemitting element and wirings according to the present invention;

FIG. 32 is a plan view showing another exemplary relation between alight emitting element and wirings according to the present invention;

FIG. 33 is a plan view showing still another exemplary relation betweena light emitting element and wirings according to the present invention;

FIG. 34 is a circuit diagram showing an exemplary relation between alight emitting element and a drive circuit according to the presentinvention:

FIG. 35 is a schematic plan view showing an exemplary wiring circuitdiagram and an electrical connection representative of a relationbetween a light emitting element and a drive circuit according to thepresent invention;

FIG. 36 is a circuit diagram showing another exemplary relation betweena light emitting element and a drive circuit according to the presentinvention;

FIG. 37 is a circuit diagram showing still another exemplary relationbetween a light emitting element and a drive circuit according to thepresent invention;

FIG. 38 is a circuit diagram showing still another exemplary relationbetween a light emitting element and a drive circuit according to thepresent invention;

FIG. 39 is a circuit diagram showing still another exemplary relationbetween a light emitting element and a drive circuit according to thepresent invention:

FIG. 40 is a sectional view showing an exemplary arrangement of lightemitting elements according to the present invention;

FIG. 41 is a sectional view showing another exemplary arrangement oflight emitting elements according to the present invention:

FIG. 42 is a sectional view showing still another exemplary arrangementof light emitting elements according to the present invention;

FIG. 43 is a sectional view showing still another exemplary arrangementof light emitting elements according to the present invention;

FIG. 44 is a sectional view showing still another exemplary arrangementof light emitting elements according to the present invention;

FIG. 45 is a sectional view showing still another exemplary arrangementof light emitting elements according to the present invention;

FIG. 46 is a sectional view showing still another exemplary arrangementof light emitting elements according to the present invention;

FIG. 47 is a sectional view showing an exemplary structure andarrangement of a light emitting element according to the presentinvention;

FIG. 48 is a sectional view showing an exemplary structure of a lightemitting element according to the present invention:

FIG. 49 is a sectional view showing another exemplary structure of alight emitting element according to the present invention;

FIG. 50 is a plan view showing still another exemplary structure of alight emitting element according to the present invention;

FIG. 51 is a sectional view showing an exemplary first step of a seriesof fabrication procedures for a light emitting element according to afirst embodiment of the present invention;

FIG. 52 is a sectional view showing a second step of the samefabrication procedures; and

FIG. 53 is a sectional view showing a third step of the same fabricationprocedures.

BEST MODE FOR CARRYING OUT THE INVENTION

Now, the present invention will be explained below in more detail withreference to the accompanying drawings in accordance with theembodiments.

FIGS. 1( a) to 8(h) are sectional views showing a layer structure of alight emitting element in an organic EL device according to the presentinvention.

The structure shown in FIG. 1( a) is configured such that a lowerelectrode 2, a light emitting layer 9 serving as both a hole injectionlayer and an electron transport layer, and a transparent electrode layer4 are sequentially formed on a base assembly 1. In this structure, thetransparent electrode layer 4 employs an oxide material of In and Snhaving a composition of In_(2-x)Sn_(x)O_(3-y) (0.05≦y≦0.2) (hereinafterditto with the transparent electrode layer 4), where x is defined suchthat 0<x<1, preferably such that 0<x<0.3. FIG. 1( b) shows an example inwhich an anode buffer layer 15 is inserted between the light emittinglayer 9 serving as both a hole injection layer and an electron transportlayer and the transparent electrode layer 4 in the multilayer structureof FIG. 1( a). FIG. 1( c) shows a structure having a protective layer 16disposed on top of the multilayer structure of FIG. 1( a). FIG. 1( d)shows a structure having the protective layer 16 disposed on top of themultilayer structure of FIG. 1( b). FIGS. 1( e), 1(f), 1(g), and 1(h)show examples in which an enhanced hygroscopic layer 18 is provided onthe transparent electrode layer 4 side opposite to the light emittinglayer 9 in FIGS. 1( a), 1(b), 1(c), and 1(d), respectively.

The structure shown in FIG. 2( a) is configured such that the lowerelectrode 2, a light emitting layer 10 serving: also as an electrontransport layer, a hole injection layer 8, and the transparent electrodelayer 4 are sequentially formed on the base assembly 1. FIG. 2( b) showsan example in which the anode buffer layer 15 is inserted between thehole injection layer 8 and the transparent electrode layer 4 in themultilayer structure of FIG. 2( a). FIG. 2( c) shows a structure havingthe protective layer 16 disposed on top of: the multilayer structure ofFIG. 2( a). FIG. 2( d) shows a structure having the protective layer 16disposed on top of the multilayer structure of FIG. 2( b). FIGS. 2( e),2(f), 2(g), and 2(h) show examples in which the enhanced hygroscopiclayer 18 is provided on the transparent electrode layer 4 side oppositeto the light emitting layer 10 in FIGS. 2( a), 2(b), 2(c), and 2(d),respectively.

The structure shown in FIG. 3( a) is configured such that the lowerelectrode 2, an electron transport layer 6, a light emitting layer 11serving also as a hole injection layer, and the transparent electrodelayer 4 are sequentially formed on the base assembly 1. FIG. 3( b) showsan example in which the anode buffer layer 15 is inserted between thelight emitting layer 11 and the transparent electrode layer 4 in themultilayer structure of FIG. 3( a). FIG. 3( c) shows a structure havingthe protective layer 16 disposed on top of the multilayer structure ofFIG. 3( a). FIG. 3( d) shows a structure having the protective layer 16disposed on top of the multilayer structure of FIG. 3( b). FIGS. 3( e),3(f), 3(g), and 3(h) show examples in which the enhanced hygroscopiclayer 18 is provided on the transparent electrode layer 4 side oppositeto the light emitting layer 11 in FIGS. 3( a), 3(b), 3(c), and 3(d),respectively.

The structure shown in FIG. 4( a) is configured such that the lowerelectrode 2, the electron transport layer 6, a light emitting layer 7,the hole injection layer 8, and the transparent electrode layer 4 aresequentially formed on the base assembly 1. FIG. 4( b) shows an examplein which the anode buffer layer 15 is inserted between the holeinjection layer 8 and the transparent electrode layer 4 in themultilayer structure of FIG. 4( a). FIG. 4( c) shows a structure havingthe protective layer 16 disposed on top of the multilayer structure ofFIG. 4( a). FIG. 4( d) shows a structure having the protective layer 16disposed on top of the multilayer structure of FIG. 4( b). FIGS. 4( e),4(f), 4(g), and 4(h) show examples in which the enhanced hygroscopiclayer 18 is provided on the transparent electrode layer 4 side oppositeto the light emitting layer 7 in FIGS. 4( a), 4(b), 4(c), and 4(d),respectively.

The structure shown in FIG. 5( a) is configured such that thetransparent electrode layer 4, the light emitting layer 9 serving alsoas both a hole injection layer and an electron transport layer, and anupper electrode 17 are sequentially formed on the base assembly 1. FIG.5( b) shows an example in which the anode buffer layer 15 is insertedbetween the light emitting layer 9 serving also as both a hole injectionlayer and an electron transport layer and the transparent electrodelayer 4 in the multilayer structure of FIG. 5( a). FIG. 5( c) shows astructure having the protective layer 16 disposed on top of themultilayer structure of FIG. 5( a). FIG. 5( d) shows a structure havingthe protective layer 16 disposed on top of the multilayer structure ofFIG. 5( b). FIGS. 5( e), 5(f), 5(g), and 5(h) show examples in which theenhanced hygroscopic layer 18 is provided between the base assembly 1and the transparent electrode layer 4 in FIGS. 5( a), 5(b), 5(c), and5(d), respectively.

The structure shown in FIG. 6( a) is configured such that thetransparent electrode layer 4, the hole injection layer 8, the lightemitting layer 10 serving also as an electron transport layer, and theupper electrode 17 are sequentially formed on the base assembly 1. FIG.6( b) shows an example in which the anode buffer layer 15 is insertedbetween the hole injection layer 8 and the transparent electrode layer 4in the multilayer structure of FIG. 6( a). FIG. 6( c) shows a structurehaving the protective layer 16 disposed on top of the multilayerstructure of FIG. 6( a). FIG. 6( d) shows a structure having theprotective layer 16 disposed on top of: the multilayer structure of FIG.6( b). FIGS. 6( e), 6(f), 6(g), and 6(h) show examples in which theenhanced hygroscopic layer. 18 is provided between the base assembly 1and the transparent electrode layer 4 in FIGS. 6( a), 6(b), 6(c), and6(d), respectively.

The structure shown in FIG. 7( a) is configured such that thetransparent electrode layer 4, the light emitting layer 11 serving alsoas a hole injection layer, the electron transport layer 6, and the upperelectrode 17 are sequentially formed on the base assembly 1. FIG. 7( b)shows an example in which the anode buffer layer 15 is inserted betweenthe light emitting layer 11 serving also as a hole injection layer andthe transparent electrode layer 4 in the multilayer structure of FIG. 7(a). FIG. 7( c) shows a structure having the protective layer 16 disposedon top of the multilayer structure of FIG. 7( a). FIG. 7( d) shows astructure having the protective layer 16 disposed on top of themultilayer structure of FIG. 7( b). FIGS. 7( e), 7(f), 7(g), and 7(h)show examples in which the enhanced hygroscopic layer 18 is providedbetween the base assembly 1 and the transparent electrode layer 4 inFIGS. 7( a), 7(b), 7(c), and 7(d), respectively.

The structure shown in FIG. 8( a) is configured such that thetransparent electrode layer 4, the hole injection layer 8, the lightemitting layer 7, the electron transport layer 6, and the upperelectrode 17 are sequentially formed on the base assembly 1. FIG. 8( b)shows an example in which the anode buffer layer 15 is inserted betweenthe hole injection layer 8 and the transparent electrode layer 4 in themultilayer structure of FIG. 8( a). FIG. 8( c) shows a structure havingthe protective layer 16 disposed on top of the multilayer structure ofFIG. 8( a). FIG. 8( d) shows a structure having the protective layer 16disposed on top of the multilayer structure of FIG. 8( b). FIGS. 8( e),8(f), 8(g), and 8(h) show examples in which the enhanced hygroscopiclayer 18 is provided between the base assembly 1 and the transparentelectrode layer 4 in FIGS. 8( a), 8(b), 8(c), and 8(d), respectively.

FIGS. 9( a) and 9(b) are schematic sectional and plan views each showingthe structure of a light emitting element 19 in an organic EL deviceaccording to an embodiment of the present invention. In this structure,the base assembly 1 is an object for forming a light emitting element ona surface thereof, including a substrate or one having film or anelement formed on the substrate (hereinafter ditto with the baseassembly 1). On the base assembly 1, there is formed a lower electrodepattern 2 a. On the lower electrode pattern 2 a, there is formed a lightemitting material layer pattern 3 a. The light emitting material layerpattern 3 a contains at least a light emitting layer, and may alsocontain an electron transport layer or a hole injection layer inaddition to the light emitting layer (hereinafter ditto with the lightemitting material layer pattern 3 a). The light emitting material layerpattern 3 a is larger than the lower electrode pattern 2 a, covering theentire region of the lower electrode pattern 2 a. In other words, alight emitting material layer pattern end 3 b stays outside a lowerelectrode pattern end 2 b over the entire region. On top of the lightemitting material layer pattern 3 a, there is formed a transparentelectrode pattern 4 a. In the figure, the transparent electrode pattern4 a is shown as if it is not patterned; however, this means that thepattern is too large to be illustrated as patterned within the rangeshown in the figure.

In this arrangement, an In_(2-x)Sn_(x)O_(3-y) (0.05≦y≦0.2), which isdeficient in oxygen to be thereby hygroscopic, is formed on the entireregion of the lower electrode pattern 2 a and the light emittingmaterial layer pattern 3 a. This allows the In_(2-x)Sn_(x)O_(3-y)(0.05≦y≦0.2) to absorb a trace amount of moisture present in thevicinity of the light emitting material layer and thereby keep moisturefrom the light emitting material.

Here, such a case was shown in which the entire region of the lowerelectrode pattern 2 a is covered with the light emitting material layerpattern 3 a. However, this embodiment also includes the case where partof the lower electrode pattern 2 a is not covered with the lightemitting material layer pattern 3 a. Additionally, in the foregoing,such a case was shown in which the entire region of the light emittingmaterial layer pattern 3 a is covered with the transparent electrodepattern 4 a; however, this embodiment also includes the case where partof the light emitting material layer pattern 3 a is not covered with thetransparent electrode pattern 4 a.

On the other hand, as shown in the schematic sectional view shown inFIG. 9( c), the enhanced hygroscopic layer 18 can also be provided onthe transparent electrode pattern 4 a of the In_(2-x)Sn_(x)O_(3-y)(0.05≦y≦0.2). In this case, the enhanced hygroscopic layer accepts themoisture absorbed by the transparent electrode layer 4 and thereby actto further keep moisture from the light emitting material.

In order to entirely block the entrance of moisture and oxygen in theair from above the transparent electrode pattern 4 a into the lowerelectrode pattern 2 a and the light emitting material layer pattern 3 a,it is also possible to provide a protective layer (not shown) on thetransparent electrode pattern 4 a or the enhanced hygroscopic layer 18.

FIGS. 10( a) and 10(b) are schematic sectional and plan views eachshowing the structure of a light emitting element 19 in an organic ELdevice according to an embodiment of the present invention. The lowerelectrode pattern 2 a is formed on the base assembly 1, and the lightemitting material layer pattern 3 a is formed on the lower electrodepattern 2 a. The light emitting material layer pattern 3 a is largerthan the lower electrode pattern 2 a, covering the entire region of thelower electrode pattern 2 a. In the figure, the light emitting materiallayer pattern 3 a is shown as if it is not patterned: however, thismeans that the pattern is too large to be illustrated as patternedwithin the range shown in the figure. The transparent electrode pattern4 a is formed on the light. emitting material layer pattern 3 a. Thetransparent electrode pattern 4 a is smaller than the light emittingmaterial layer pattern 3 a but larger than the lower electrode pattern 2a. Additionally, the entire region of the lower electrode pattern 2 a iscovered with the transparent electrode pattern 4 a. In other words, thelower electrode pattern end 2 b is located inside a transparentelectrode pattern end 4 b over the entire region.

In this arrangement, the In_(2-x)Sn_(x)O_(3-y) (0.05≦y≦0.2), which isdeficient in oxygen to be thereby hygroscopic, is formed on the entireregion of the lower electrode pattern 2 aand the light emitting portion.In this structure, the light emitting portion is a portion of the lightemitting material layer pattern 3 a which is sandwiched between thelower electrode pattern 2 a and the transparent electrode pattern 4 aand which emits light by the application of a voltage between the lowerelectrode pattern 2 a and the transparent electrode pattern 4 a. In thiscase, it generally coincides with the portion of the light emittingmaterial layer that is in contact with the lower electrode pattern 2 a.This structure allows the In_(2-x)Sn_(x)O_(3-y) (0.05≦y≦0.2) to absorb atrace amount of moisture present in the vicinity of the light emittingportion of the light emitting material layer and thereby keep moisturefrom the light emitting material layer.

This structure does not require the light emitting material layerpattern 3 a to be patterned with accuracy so that it entirely covers thelower electrode pattern 2 a and is covered with the transparentelectrode pattern 4 a, thereby being easily manufactured and reduced inmanufacturing costs when compared with the structure shown in FIGS. 9(a) and 9(b). However, the transparent electrode pattern 4 a cannotabsorb moisture from the portion of the light emitting material layerpattern 3 a which is not covered with the transparent electrode pattern4 a. This region is located apart from the light emitting portion andnot directly related to light emission. However, any corrosion in thisregion may trigger the p eling or the like of the lower electrodepattern 2 a, thereby exerting an effect on emission characteristics. Touse this structure, it is desirable to employ for the light emittinglayer a material that is resistant to corrosion by moisture or oxygen.

Here, such a case has been shown in which the entire region of the lowerelectrode pattern 2 a is covered with the light emitting material layerpattern 3 a; however, this embodiment also includes the case where partof the lower electrode pattern 2 a is not covered with the lightemitting material layer pattern 3 a. Additionally, in the foregoing,such a case has been shown in which the entire region of the transparentelectrode pattern 4 a is formed on the light emitting material layerpattern 3 a; however, this embodiment also includes the case where partof the transparent electrode pattern 4 a is not formed on the lightemitting material layer pattern 3 a.

This embodiment shown in FIGS. 10( a) and 10(b) can also be modified asfollows. That is, as shown in the sectional view shown in FIG. 10( c),the enhanced hygroscopic layer 18 can also be provided on thetransparent electrode pattern 4 a. In this case, the enhancedhygroscopic layer 18 accepts the moisture absorbed by the transparentelectrode pattern 4 a and serves to further keep moisture from the lightemitting material.

In order to entirely block the entrance of moisture and oxygen in theair into the lower electrode pattern 2 a and the light emitting materiallayer pattern 3 a, it is also possible to provide a protective layer(not shown) on the transparent electrode pattern 4 a or the enhancedhygroscopic layer 18.

FIGS. 11( a) and 11(b) are schematic sectional and plan views eachshowing the structure of a light emitting element 19 in an organic ELdevice according to an embodiment of the present invention. The lowerelectrode pattern 2 a is formed on the base assembly 1, and the lightemitting material layer pattern 3 a is formed on the lower electrodepattern 2 a. Such a case is shown here in which the entirety of thelight emitting material layer pattern 3 a is formed on the lowerelectrode pattern 2 a. Around the light emitting material layer pattern3 a, there is formed an insulating layer pattern 5 a such that aninsulating layer pattern end 5 b is in contact with the light emittingmaterial layer pattern end 3 b. The transparent electrode pattern 4 a isformed on the light emitting material layer pattern 3 a so as to coverthe entirety thereof.

In this arrangement, the In_(2-x)Sn_(x)O_(3-y) (0.05≦y≦0.2), which isdeficient in oxygen to be thereby hygroscopic, is formed on the entireregion of the lower electrode pattern 2 a and the light emittingmaterial layer pattern 3 a. This allows the In_(2-x)Sn_(x)O_(3-y)(0.05≦y≦0.2) to absorb a trace amount of moisture present in thevicinity of the light emitting material layer and thereby keep moisturefrom the light emitting material.

This structure is configured such that the lower electrode pattern 2 aand the light emitting material layer pattern 3 a are embedded in theinsulating layer pattern 5 a, thereby allowing the upper portion of theelement to be relatively flattened. However, the insulating layerpattern 5 a needs to be employed and provided through an additionalstep, thereby causing an increase in manufacturing costs by that amount.

Here, such a case was shown in which the entire region of the lightemitting material layer pattern 3 a is formed on the lower electrodepattern 2 a; however, this embodiment also includes the case where partof the light emitting material layer pattern 3 a is not formed on thelower electrode pattern 2 a. Additionally, in the foregoing, such a casewas shown in which the entire region of the light emitting materiallayer pattern 3 a is covered with the transparent electrode pattern 4 a;however, this embodiment also includes the case where part of the lightemitting material layer pattern 3 a is not covered with the transparentelectrode pattern 4 a.

This embodiment shown in FIGS. 11( a) and 11(b) can also be modified asfollows. That is, as shown in the sectional view shown in FIG. 11( c),the enhanced hygroscopic layer 18 can also be provided on thehygroscopic transparent electrode pattern 4 a. In this case, theenhanced hygroscopic layer accepts the moisture absorbed by thetransparent electrode pattern 4 a and serves to further keep moisturefrom the light emitting material.

In order to entirely block the entrance of moisture and oxygen in theair into the lower electrode pattern 2 a and the light emitting materiallayer pattern 3 a, it is also possible to provide a protective layer(not shown) on the transparent electrode pattern 4 a or the enhancedhygroscopic layer 18.

The structures shown in FIGS. 12( a), 12(b), and 12(c) are variations ofthe embodiments shown in FIGS. 11( a), 11(b), and 11(c), with the end 5b of the insulating layer pattern 5 a staying on the light emittingmaterial layer pattern 3 a. The insulating layer and the light emittingmaterial pattern overlapping each other makes it possible to prevent theoccurrence of a leakage current between the lower electrode pattern 2 aand the transparent electrode pattern 4 a, which may result from amanufacturing error. However, the presence of the insulating layer andthe light emitting material pattern overlapping each other causes theupper surface of the light emitting element 19 to deteriorate inflatness more than that of FIG. 11.

FIGS. 13( a) and 13(b) are schematic sectional and plan views eachshowing the structure of a light emitting element 19 in an organic ELdevice according to an embodiment of the present invention. The lowerelectrode pattern 2 a is formed on the base assembly 1, and the lightemitting material layer pattern 3 a is formed on the lower electrodepattern 2 a. The light emitting material layer pattern 3 a covers theentire region of the lower electrode pattern 2 a. On top thereof, thetransparent electrode pattern 4 a is formed so as to cover the entirepattern of the lower electrode pattern 2 a. On the light emittingmaterial layer pattern 3 a around the transparent electrode pattern 4 a,formed is the insulating layer pattern 5 a such that its end 5 b is incontact with the transparent electrode pattern end 4 b. Although notcompletely illustrated, the insulating layer pattern 5 a is formed so asto cover the entirety of such a portion of the light emitting materiallayer pattern 3 a that is not covered with the transparent electrodepattern 4 a.

In this arrangement, the In_(2-x)Sn_(x)O_(3-y) (0.05≦y≦0.2), which isdeficient in oxygen to be thereby hygroscopic, is formed on the entireregion of the lower electrode pattern 2 a and the entire region of thelight emitting material layer pattern 3 a that is not covered with theinsulating layer. This allows the In_(2-x)Sn_(x)O_(3-y) to absorb atrace amount of moisture present in the vicinity of the light emittingportion of the light emitting material layer and thereby keep moisturefrom the light emitting material of that region.

Here, such a case was shown in which the entire region of the lowerelectrode pattern 2 a is covered with the light emitting material layerpattern 3 a; however, this embodiment also includes the case where partof the lower electrode pattern 2 a is not covered with the lightemitting material layer pattern 3 a. Additionally, in the foregoing,such a case was shown in which the entire region of the transparentelectrode pattern 4 a is formed on the light emitting material layerpattern 3 a; however, this embodiment also includes the case where partof the transparent electrode pattern 4 a is not formed on the lightemitting material layer pattern 3 a.

This embodiment shown in FIGS. 13( a) and 13(b) can also be modified asfollows. That is, as shown in the sectional view shown in FIG. 13( c),the enhanced hygroscopic layer 18 can also be provided on thehygroscopic transparent electrode layer 4 in this case, the enhancedhygroscopic layer accepts the moisture absorbed by the transparentelectrode layer 4 and serves to further keep moisture from the lightemitting material.

In order to entirely block the entrance of moisture and oxygen in theair into the lower electrode pattern 2 a and the light emitting materiallayer pattern 3 a, it is also possible to provide a protective layer(not shown) on the transparent electrode pattern 4 a or the enhancedhygroscopic layer 18.

The structures shown in FIGS. 14( a), 14(b), and 14(c) are variations ofthe embodiments shown in FIGS. 13( a), 13(b), and 13(c). In thisembodiment, the insulating layer pattern and the transparent electrodepattern are formed to overlap each other so that the insulating layerpattern end 5 b is located inside the transparent electrode pattern end4 b. The insulating layer pattern 5 a and the transparent electrodepattern 4 a overlapping each other makes it possible to prevent theoccurrence of a gap between the insulating layer pattern end 5 b and thetransparent electrode pattern-end 4 b, which may result from amanufacturing error, thereby reducing the possibility of corrosion ofthe light emitting material layer. However, the presence of theinsulating layer and the light emitting material pattern overlappingeach other causes the upper surface of the light emitting element 19 todeteriorate in flatness more than that of FIG. 13.

FIGS. 15( a) and 15(b) are sectional and plan views each showing anarrangement of light emitting elements in an organic EL device accordingto an embodiment of the present invention. In each single light emittingelement, the lower electrode pattern 2 a is formed on the base assembly1, and the light emitting material layer pattern 3 a is formed on thelower electrode pattern 2 a so as to cover the entire region thereof.Furthermore, on the light emitting material layer pattern 3 a, formed isthe transparent electrode pattern 4 a so as to cover the entire regionthereof. Such elements are arranged in the horizontal and verticaldirections as shown in the figure. Here, such an example was shown inwhich the light emitting elements are arranged vertically in fivecolumns and horizontally in four rows; however, the number of rows andcolumns can be selected freely.

FIGS. 16( a) and 16(b) are sectional and plan views each showing anarrangement of light emitting elements in an organic EL device accordingto an embodiment of the present invention. In this embodiment, the lowerelectrode pattern 2 a is formed on the base assembly 1, and on the lowerelectrode pattern 2 a, formed is the light emitting material layerpattern 3 a so as to cover the top of the lower electrode pattern 2 aand the top of the base assembly between the lower electrode patterns 2a. That is, the light emitting material layer pattern 3 a covers aplurality of lower electrode patterns 2 a. On the light emittingmaterial layer pattern 3 a, formed is the transparent electrode pattern4 a so as to cover the entire region thereof. A single transparentelectrode pattern 4 a covers a plurality of lower electrode patterns 2 aand light emitting material layer patterns 3 a. Here, such an examplewas shown in which the light emitting elements are arranged verticallyin five columns and horizontally in four rows; however, the number ofrows and columns can be selected freely. Additionally, in the foregoing,the light emitting material layer pattern 3 a and the transparentelectrode pattern 4 a are common to all the light emitting elements, butnot limited thereto, and may cover only a plurality of light emittingelements.

FIGS. 17( a) and 17(b) are sectional and plan views each showing anarrangement of light emitting elements in an organic EL device accordingto an embodiment of the present invention. In this embodiment, the lowerelectrode pattern 2 a is formed on the base assembly 1, and on eachlower electrode pattern 2 a, formed is the light emitting material layerpattern 3 a so as to cover the entire region thereof. On the lightemitting material layer pattern 3 a, formed is the transparent electrodepattern 4 a so as to cover the top of the light emitting material layerpattern 3 a and the top of the base assembly 1 between the lightemitting material layer patterns 3 a. A single transparent electrodepattern 4 a covers a plurality of lower electrode patterns 2 a and aplurality of light emitting material layer patterns 3 a. Here, such anexample was shown in which the light emitting elements are arrangedvertically in five columns and horizontally in four rows; however, thenumber of rows and columns can be selected freely. Additionally, in theforegoing, the transparent electrode pattern 4 a is common to all thelight emitting elements, but not limited thereto, and may cover only aplurality of light emitting elements.

FIGS. 18( a) and 18(b) are sectional and plan views each showing thestructure of a light emitting element 19 in an organic EL deviceaccording to an embodiment of the present invention. As shown in FIG.18, the transparent electrode pattern 4 a is formed on the base assembly1, and the light emitting material layer pattern 3 a is formed on thetransparent electrode pattern 4 a so as to cover part thereof. There isformed an upper electrode pattern 17 a on the light emitting materiallayer pattern 3 a to cover part thereof. Accordingly, the light emittingmaterial layer pattern 3 a is smaller than the transparent electrodepattern 4 a, while the upper electrode pattern 17 a is smaller than thelight emitting material layer pattern 3 a.

In this arrangement, the In_(2-x)Sn_(x)O_(3-y) (0.05≦y≦0.2), which isdeficient in oxygen to be thereby hygroscopic, is formed under theentire region of the lower electrode pattern 2 a and the light emittingmaterial layer pattern. 3 a. This allows the In_(2-x)Sn_(x)O_(3-y) toabsorb a trace amount of moisture present in the vicinity of the lightemitting material layer and thereby keep moisture from the lightemitting material.

Here, such a case was shown in which the entire region of the lightemitting material layer pattern 3 a is formed on the transparentelectrode pattern 4 a; however, this embodiment also includes the casewhere part of the light emitting material layer pattern 3 a is notformed on the transparent electrode pattern 4 a. Additionally, in theforegoing, such a case was shown in which the entire region of the upperelectrode pattern 17 a is formed on the light emitting material layerpattern 3 a; however, this embodiment also includes the case where partof the upper electrode pattern 17 a is not formed on the light emittingmaterial layer pattern 3 a.

This embodiment shown in FIGS. 18( a) and 18(b) can also be modified asfollows. That is, as shown in the sectional view shown in FIG. 18( c),the enhanced hygroscopic layer 18 can also be provided under thehygroscopic transparent electrode pattern 4 a. In this case, theenhanced hygroscopic layer 18 accepts the moisture absorbed by thetransparent electrode pattern 4 a and serves to further keep moisturefrom the light emitting material.

In order to entirely block the entrance of moisture and oxygen in theair into the upper electrode pattern 17 a and the light emittingmaterial layer pattern 3 a, it is also possible to provide a protectivelayer (not shown) on the multilayer structure shown.

FIGS. 19( a) and 19(b) are sectional and plan views each showing thestructure of a light emitting element 19 in an organic EL deviceaccording to an embodiment of the present invention. The transparentelectrode pattern 4 a is formed on the base assembly 1, and the lightemitting material layer pattern 3 a is formed on the transparentelectrode pattern 4 a so as to completely cover the top of thetransparent electrode pattern 4 a. Accordingly, the light emittingmaterial layer pattern 3 a is larger than the transparent electrodepattern 4 a. On the light emitting material layer pattern 3 a, form d isthe upper electrode pattern 17 a so as to cover part of the top of thelight emitting material layer pattern 3 a. Accordingly, the upperelectrode pattern 17 a is smaller than the light emitting material layerpattern 3 a.

In this arrangement, the In_(2-x)Sn_(x)O_(3-y) (0.05≦y≦0.2), which isdeficient in oxygen to be thereby hygroscopic, is formed under the upperelectrode pattern 17 a and the light emitting portion of the lightemitting material layer pattern 3 a. This allows theIn_(2-x)Sn_(x)O_(3-y) to absorb a trace amount of moisture present inthe vicinity of the light emitting material layer and thereby keepmoisture from the light emitting material.

This embodiment can make the light emitting material layer pattern 3 alarger than that shown in FIGS. 18( a) and (b), thereby facilitating theformation of the light emitting material layer pattern 3 a and providinga merit of a broadened scope of selection of the methods formanufacturing the light emitting material layer pattern 3 a. However,since a portion of the light emitting material layer pattern 3 a may notbe formed on the transparent electrode pattern 4 a, the light emittingmaterial layer pattern 3 a may need to use a material having a bettermoisture resistance.

Here, such a case was shown in which the entire region of thetransparent electrode pattern 4 a is covered with the light emittingmaterial layer; however, this embodiment also includes the case wherepart of the transparent electrode pattern 4 a is not covered with thelight emitting material layer. Additionally, in the foregoing, such acase was shown in which the entire region of the upper electrode pattern17 a is formed on the light emitting material layer pattern 3 a;however, this embodiment also includes the case where part of the upperelectrode pattern 17 a is not formed on the light emitting materiallayer pattern 3 a.

This embodiment shown in FIGS. 19( a) and 19(b) can also be modified asfollows. That is, as shown in the sectional view shown in FIG. 19( c),the enhanced hygroscopic layer 18 can also be provided between thehygroscopic transparent electrode layer 4 and the base assembly 1. Inthis case, the enhanced hygroscopic layer accepts the moisture absorbedby the transparent electrode layer 4 and serves to further keep moisturefrom the light emitting material.

In order to entirely block the entrance of moisture and oxygen in theair into the upper electrode pattern 17 a and the light emittingmaterial layer pattern 3 a, it is also possible to provide a protectivelayer (not shown) on the multilayer structure shown.

FIGS. 20( a) and 20(b) are sectional and plan views each showing thestructure of a light emitting element 19 in an organic EL deviceaccording to an embodiment of the present invention. The transparentelectrode pattern 4 a is formed on the base assembly 1, and the lightemitting material layer pattern 3 a is formed on the transparentelectrode pattern 4 a so as to completely cover the transparentelectrode pattern 4 a. On the light emitting material layer pattern 3 a,formed is the upper electrode pattern 17 a so as to completely cover thetop of the light emitting material layer pattern 3 a. Accordingly, thelight emitting material layer pattern 3 a is larger than the transparentelectrode pattern 4 a, while the upper electrode pattern 17 a is largerthan the light emitting material layer pattern 3 a.

In this arrangement, the In_(2-x)Sn_(x)O_(3-y) (0.05≦y≦0.2), which isdeficient in oxygen to be thereby hygroscopic, is formed under the lightemitting material layer pattern 3 a serving as a light emitting portion.This allows the In_(2-x)Sn_(x)O_(3-y) (0.05≦y≦0.2) to absorb a traceamount of moisture present in the vicinity of the light emittingmaterial layer and thereby keep moisture from the light emittingmaterial.

This arrangement can also make the light emitting material layer pattern3 a and the upper electrode pattern 17 a larger than that shown in FIGS.18( a) and (b), thereby facilitating the formation of the light emittingmaterial layer pattern 3 a and the upper electrode pattern 17 a andproviding a merit of a broadened scope of selection of the methods formanufacturing the light emitting material layer pattern 3 a and theupper electrode pattern 17 a. However, since some portions of the lightemitting material layer pattern 3 a and the upper electrode pattern 17 aare not formed on the transparent electrode pattern 4 a, the lightemitting material layer pattern 3 a may possibly need to use a materialhaving a better moisture resistance.

Here, such a case was shown in which the entire region of thetransparent electrode pattern 4 a is covered with the light emittingmaterial layer; however, this embodiment also includes the case wherepart of the transparent electrode pattern 4 a is not covered with thelight emitting material layer. Additionally, in the foregoing, such acase was shown in which the entire region of the light emitting materiallayer pattern 3 a is covered with the upper electrode pattern 17 a;however, this embodiment also includes the case where part of the lightemitting material layer pattern 3 a is not covered with the upperelectrode pattern 17 a.

This embodiment shown in FIGS. 20( a) and 20(b) can also be modified asfollows. That is, as shown in the sectional view shown in FIG. 20( c),the enhanced hygroscopic layer 18 can also be provided between thehygroscopic transparent electrode layer 4, and the base assembly 1. Inthis case, the enhanced hygroscopic layer accepts the moisture absorbedby the transparent electrode layer 4 and serves to further keep moisturefrom the light emitting material.

In order to entirely block the entrance of moisture and oxygen in theair into the upper electrode pattern 17 a and the light emittingmaterial layer pattern 3 a, it is also possible to provide a protectivelayer (not shown) on the multilayer structure shown.

FIGS. 21( a) and 21(b) are sectional and plan views each showing thestructure of a light emitting element 19 in an organic EL deviceaccording to an embodiment of the present invention. The transparentelectrode pattern 4 a is formed on the base assembly 1, and the lightemitting material layer pattern 3 a is formed on the transparentelectrode pattern 4 a so as to completely cover the transparentelectrode pattern 4 a. Accordingly, the light emitting material layerpattern 3 a is larger than the transparent electrode pattern 4 a. On thelight emitting material layer pattern 3 a, formed is the upper electrodepattern 17 a so as to cover the top of the transparent electrode pattern4 a. The upper electrode pattern 17 a is smaller than the light emittingmaterial layer pattern 3 a.

In this arrangement, the In_(2-x)Sn_(x)O_(3-y) (0.05≦y≦0.2), which isdeficient in oxygen to be thereby hygroscopic, is formed under the lightemitting material layer pattern 3 a serving as the light emittingportion. This allows the In_(2-x)Sn_(x)O_(3-y) (0.05≦y≦0.2) to absorb atrace amount of moisture present in the vicinity of the light emittingmaterial layer and thereby keep moisture from the light emittingmaterial.

This arrangement can also make the light emitting material layer pattern3 a and the upper electrode pattern 17 a larger than that shown in FIGS.18( a) and (b), thereby facilitating the formation of the light emittingmaterial layer pattern 3 a and the upper electrode pattern 17 a andproviding a merit of a broadened scope of selection of the methods formanufacturing the light emitting material layer pattern 3 a and theupper electrode pattern 17 a. However, since some portions of the lightemitting material layer pattern 3 a and the upper electrode pattern 17 amay not be formed on the transparent electrode pattern 4 a, the lightemitting material layer pattern 3 a may possibly need to use a materialhaving a better moisture resistance.

This embodiment shown in FIGS. 21( a) and 21(b) can also be modified asfollows. That is, as shown in the sectional view shown in FIG. 21( c),the enhanced hygroscopic layer 18 can also be provided between thetransparent electrode pattern 4 a and light emitting material layerpattern 3 a and the base assembly 1. In this case, the enhancedhygroscopic layer accepts the moisture absorbed by the transparentelectrode pattern 4 a and serves to further keep moisture from the lightemitting material. In addition, it is also possible to provide animproved durability to the light emitting material by absorbing moisturefrom the region of the light emitting material layer pattern 3 a that isnot in contact with the transparent electrode pattern 4 a.

In order to entirely block the entrance of moisture and oxygen in theair into the upper electrode pattern 17 a and the light emittingmaterial layer pattern 3 a, it is also possible to provide a protectivelayer (not shown) on the multilayer structure shown.

FIGS. 22( a) and 22(b) are sectional and plan views each showing thestructure of a light emitting element 19 in an organic EL deviceaccording to an embodiment of the present invention. The transparentelectrode pattern 4 a is formed on the base assembly 1, and the lightemitting material layer pattern 3 a is formed on the transparentelectrode pattern 4 a so as to cover part of the transparent electrodepattern 4 a. Accordingly, the light emitting material layer pattern 3 ais smaller than the transparent electrode pattern 4 a. The insulatinglayer pattern 5 a is formed around the light emitting material layerpattern 3 a so as to embed the light emitting material layer pattern 3 atherein. On the light emitting material layer pattern 3 a and theinsulating layer pattern 5 a, formed is the upper electrode pattern 17 aso as to completely cover the top of the light emitting material layerpattern 3 a. Accordingly, the upper electrode pattern 17 a is largerthan the light emitting material layer pattern 3 a.

In this arrangement, the In_(2-x)Sn_(x)O_(3-y) (0.05≦y≦0.2), which isdeficient in oxygen to be thereby hygroscopic, is formed under the lightemitting material layer pattern 3 a. This allows theIn_(2-x)Sn_(x)O_(3-y) (0.05≦y≦0.2) to absorb a trace amount of moisturepresent in the vicinity of the light emitting material layer and therebykeep moisture from the light emitting material.

This embodiment allows the transparent electrode pattern 4 a and thelight emitting material layer pattern 3 a to be embedded in theinsulating layer pattern 5 a, thereby providing a merit of the uppersurface of the light emitting element 19 being flatter when comparedwith the cases shown in FIGS. 18 to 21. However, this embodimentrequires an additional step of embedding in the insulating layer pattern5 a, thereby causing an increase in manufacturing costs.

Here, such a case was shown in which the entire region of the lightemitting material layer pattern 3 a is formed on the transparentelectrode pattern 4 a; however, this embodiment also includes the casewhere part of the light emitting material layer pattern 3 a is notformed on the transparent electrode pattern 4 a. Additionally, in theforegoing, such a case was shown in which the entire region of the lightemitting material layer pattern 3 a is covered with the upper electrodepattern 17 a; however, this embodiment also includes the case where partof the light emitting material layer pattern 3 a is not covered with theupper electrode pattern 17 a.

This embodiment shown in FIGS. 22( a) and 22(b) can also be modified asfollows. That is, as shown in the sectional view shown in FIG. 22( c),the enhanced hygroscopic layer 18 can also be provided between thehygroscopic transparent electrode layer 4 and the base assembly 1. Inthis case, the enhanced hygroscopic layer accepts the moisture absorbedby the transparent electrode layer 4 and serves to further keep moisturefrom the light emitting material.

In order to entirely block the entrance of moisture and oxygen in theair into the upper electrode pattern 17 a and the light emittingmaterial layer pattern 3 a, it is also: possible to provide a protectivelayer (not shown) on the multilayer structure shown.

The structures shown in FIGS. 23( a), 23(b), and 23(c) are variations ofthe embodiments shown in FIGS. 22( a), 22(b), and 22(c), with the end 5b of the insulating layer pattern 5 a staying on the light emittingmaterial layer pattern 3 a. The insulating layer and the light emittingmaterial pattern overlapping each other makes it possible to prevent theoccurrence of a leakage current between the upper electrode pattern 17 aand the transparent electrode pattern 4 a, which may result from amanufacturing error. However, the presence of the insulating layer andthe light emitting material pattern overlapping each other causes theupper surface of the light emitting element 19 to deteriorate inflatness more than that of FIG. 22.

FIGS. 24( a) and 24(b) are schematic sectional and plan views eachshowing the structure of a light emitting element 19 in an organic ELdevice according to an embodiment of the present invention. Thetransparent electrode pattern 4 a is formed on the base assembly 1, andthe light emitting material layer pattern 3 a is formed on thetransparent electrode pattern 4 a. The light emitting material layerpattern 3 acovers the entire region of the transparent electrode pattern4 a. On top thereof, the upper electrode pattern 17 a is formed to coverthe entire top of the transparent electrode pattern 4 a. On the lightemitting material layer pattern 3 a around the upper electrode pattern17 a, formed is the insulating layer pattern 5 a such that theinsulating layer pattern end 5 b is in contact with an upper electrodepattern end 17 b. In this arrangement, the insulating layer pattern 5 ais formed so as to cover the entire portion of the light emittingmaterial layer pattern 3 a that is not covered With the upper electrodepattern 17 a.

In this arrangement, the In_(2-x)Sn_(x)O_(3-y) (0.05≦y≦0.2), which isdeficient in oxygen to be thereby hygroscopic, is formed under the lightemitting portion of the light emitting material layer pattern 3 a. Thisallows the In_(2-x)Sn_(x)O_(3-y) (0.05≦y≦0.2) to absorb a trace amountof moisture present in the vicinity of the light emitting material layerand thereby keep moisture from the light emitting material of thatregion.

Here, such a case was shown in which the entire region of thetransparent electrode pattern 4 a is covered with the light emittingmaterial layer; however, this embodiment also includes the case wherepart of the transparent electrode pattern 4 a is not covered with thelight emitting material layer. Additionally, in the foregoing, such acase was shown: in which the entire region of the upper electrodepattern 17 a is formed on the light emitting material layer pattern 3 a;however, this embodiment also includes the case where part of the upperelectrode pattern 17 a is not formed on the light emitting materiallayer pattern 3 a.

This embodiment shown in FIGS. 24( a) and 24(b) can also be modified asfollows. That is, as shown in the sectional view shown in FIG. 24( c),the enhanced hygroscopic layer 18 can also be provided under thehygroscopic transparent electrode pattern 4 a and the light emittingmaterial layer pattern 3 a. In this case, the enhanced hygroscopic layeraccepts the moisture absorbed by the transparent electrode layer 4 andserves to further keep moisture from the light emitting material. Inaddition, it is also possible to provide an improved durability to thelight emitting material by absorbing moisture from the region of thelight emitting material layer pattern 3 a that is not in contact withthe transparent electrode pattern 4 a.

In order to entirely block the entrance of moisture and oxygen in theair into the upper electrode pattern 17 a and the light emittingmaterial layer pattern 3 a, it is also possible to provide a protectivelayer (not shown) on the multilayer structure shown.

The structures shown in FIGS. 25( a), 25(b), and 25(c) are variations ofthe embodiments shown in FIGS. 24( a), 24(b), and 24(c), with the end 5b of the insulating layer pattern 5 a staying on the upper electrodepattern 17 a. That is, in this embodiment, the insulating layer pattern5 a is formed so that its end 5 b is located on the transparentelectrode pattern end 4 b. The insulating layer pattern 5 a and theupper electrode pattern 17 a overlapping each other makes it possible toprevent the occurrence of a gap between the insulating layer pattern end5 b and the upper electrode pattern end 17 b, which may result from amanufacturing error, thereby reducing the possibility of corrosion ofthe light emitting material layer.

FIGS. 26( a) and 26(b) are sectional and plan views each showing anarrangement of light emitting elements in an organic EL device accordingto an embodiment of the present invention.

In each light emitting element, the transparent electrode pattern 4 a isformed on the base assembly 1, and the light emitting material layerpattern 3 a is formed on the transparent electrode pattern 4 a so as tocover part of the transparent electrode pattern 4 a. On the lightemitting material layer pattern 3 a, formed is the upper electrodepattern 17 a so as to cover part of the top of the light emittingmaterial layer pattern 3 a. Such elements are arranged in the horizontaland vertical directions as shown in the figure. Here, such an examplewas shown in which the light emitting elements are arranged verticallyin five columns and horizontally in four rows; however, the number ofrows and columns can be selected freely.

FIGS. 27( a) and 27(b) are sectional and plan views each showing anarrangement of light emitting elements in an organic EL device accordingto an embodiment of the present invention. The transparent electrodepattern 4 a is formed on the base assembly 1, and on the transparentelectrode pattern 4 a, formed are a plurality of light emitting materiallayer patterns 3 a in the vertical and horizontal directions. The upperelectrode pattern 17 a is formed on each light emitting material layerpattern 3 a so as to cover part of the top of the light emittingmaterial layer pattern 3 a. Here, such an example was shown in which thelight emitting elements are arranged vertically in five columns andhorizontally in four rows; however, the number of rows and columns canbe selected freely. Additionally, in the foregoing, the transparentelectrode pattern 4 a is common to all the light emitting elements, butnot limited thereto, and may cover only a plurality of light emittingelements.

FIGS. 28( a) and 28(b) are sectional and plan views each showing anarrangement of light emitting elements in an organic EL device accordingto an embodiment of the present invention. The transparent electrodepattern 4 a is formed on the base assembly 1, and on the transparentelectrode pattern 4 a, formed is the light emitting material layerpattern 3 a so as to cover most of the top of the transparent electrodepattern 4 a. On the light emitting material layer pattern 3 a, formedare a plurality of upper electrode patterns 17 a in the horizontal andvertical directions. Here, such an example was shown in which the lightemitting elements are arranged vertically in five columns andhorizontally in four rows; however, the number of rows and columns canbe selected freely. Additionally, in the foregoing, the transparentelectrode pattern 4 a and the light emitting material layer pattern 3 aare common to all the light emitting elements, but not limited thereto,and may cover only a plurality of light emitting elements.

FIGS. 29( a) and 29(b) are schematic sectional and plan views eachshowing the structure of a display device available as an organic ELdevice according to an embodiment of the present invention. The lightemitting elements are often encapsulated in an inert gas for use, withthe environment thereof being replaced and sealed by the inert gas. Thestructure shown in FIG. 29 provides an adhesive 70 around a set of aplurality of light emitting elements and a sealing member 71 thereon,thereby implementing the encapsulation of the light emitting elements. Asealing gas is filled in the encapsulated space.

Here, such a case was shown in which twenty light emitting elements areencapsulated in one sealing member 71; however, the number of lightemitting elements to be encapsulated in one sealing member 71 can beselected as appropriate.

FIG. 30( a) is a schematic view showing the structure of a lightemitting element with a drive portion in an organic EL device accordingto the present invention. In the light emitting element with a driveportion, the light emitting element 19 is connected to a current supplyelement 13, which is in turn connected to a switching element 12.

FIG. 30( b) is a plan view showing a plurality of light emittingelements each having the drive portion and arranged as described above,the light emitting elements being disposed in the horizontal andvertical directions. Here, such an example was shown in which the lightemitting elements are arranged vertically in six columns andhorizontally in three rows; however, the number of rows and columns canbe selected arbitrarily.

Referring to FIGS. 31 to 33, explained below is the planar positionalrelationship between the wirings and the light emitting elements in anorganic EL device according to the present invention.

In the example shown in FIG. 31, ground lines 22 and first switchingwirings 20 are disposed horizontally (in the figure when viewed from itsfront), while second switching wirings 21 are disposed vertically. Thelight emitting element 19 is disposed in a space defined by the latticesmade up of the vertical and horizontal wirings. The light emittingelement 19 is connected to a current supply element (not shown), whichis in turn connected to a switching element (not shown). On the otherhand, the light emitting element or the current supply element (notshown) is connected to a current source (not shown). The ground lines 22may also be arranged in the horizontal direction. Here, such an examplewas shown in which the light emitting elements 19 are arrangedvertically in two columns and horizontally in two rows; however, thenumber of rows and columns can be selected as appropriate.

In the example shown in FIG. 32, the second switching wirings 21 and theground lines 22 are disposed horizontally (in the figure when viewedfrom its front), while the first switching wirings 20 and current supplylines 23 are disposed vertically. The light emitting element 19 isdisposed in a space defined by the lattices made up of the vertical andhorizontal wirings. The light emitting element 19 is connect d to acurrent supply element (not shown), which is in turn connected to aswitching element (not shown). The ground lines 22 may also be arrangedin the vertical direction. The current supply line may also be arrangedin the horizontal direction. Here, such an example was shown in whichthe light emitting elements 19 are arranged vertically in two columnsand horizontally in two rows; however, the number of rows and columnscan be selected as appropriate.

In the example shown in FIG. 33, second switching wirings 24, servingalso as a ground line, and the current supply lines 23 are disposedhorizontally (in the figure when viewed from its front), while the firstswitching wirings 20 are disposed vertically. The light emitting element19 is disposed in a space defined by the lattices made up of thevertical and horizontal wirings. The light emitting element 19 isconnected to a current supply element (not shown), which is in turnconnected to a switching element (not shown). The current supply lines23 can also be arranged in the vertical direction. Here, such an examplehas been shown in which the light emitting elements 19 are arrangedvertically in two columns and horizontally in two rows; however, thenumber of rows and columns can be selected as appropriate. In thisarrangement, the second switching wirings 24 serving also as a groundline are a wiring to which a ground potential and a switching potentialare alternately applied in a time division manner.

The embodiment shown in FIG. 33 may also be modified as follows. Thatis, the ground line 22 is disposed in place of the second switchingwiring 24, which also serves as a ground line. In this case, forexample, a diode element such as MIM is employed as the switchingelement.

Referring to FIGS. 34 to 39, explained below is the connectionalrelationships between the light emitting element, the current supplyelement, the switching element, and the first and second switchingwirings, the current supply line and the like in an organic EL deviceaccording to the present invention.

FIG. 34 is a circuit connection diagram of a light emitting elementaccording to an embodiment of the present invention. In this circuit,such a case is shown in which a switching transistor is employed as theswitching element and a current supply transistor is employed as thecurrent supply element.

A first switching wiring 187 and a second switching wiring 188 are laidin the horizontal and vertical directions as shown. The gate portion 194a of a switching transistor 183 is connected to the first switchingwiring 187, while the drain portion 193 a is connected to the secondswitching wiring 188. The source portion 195 a is connected to the gateportion 194 b of a current supply transistor 184 and one terminal of avoltage sustain capacitor 185. The other terminal of the voltage sustaincapacitor 185 is connected to a ground 190. The drain portion 193 b ofthe current supply transistor 184 is connected to a current source 191,while the source portion 195 b is connected to the anode of a lightemitting element 182. The cathode of the light emitting element 182 isconnected to the ground 190. In this arrangement, it is assumed that thecurrent supply source and the ground potential are supplied to eachelement through conductive layers formed entirely on the substrate orthe elements or through individual wirings.

Applying a voltage to the first switching wiring 187 causes a voltage tobe applied to the gate portion 194 a of the switching transistor 183,thereby allowing the drain portion 193 a and the source portion 195 a toconduct therebetween. Applying a voltage to the second switching wiring188 under this condition causes a voltage to be applied to the sourceportion 195 a and electric charge to be accumulated in the voltagesustain capacitor 185. Even when the voltage applied to the firstswitching wiring 187 or the second switching wiring 188 is turned off,this allows a voltage to continue being applied to the gate portion 194b of the current supply transistor 184 until the electric chargeaccumulated in the voltage sustain capacitor 185 disappears. A voltageapplied to the gate portion 194 b of the current supply transistor 184causes the drain portion 193 b and the source portion 195 b to conducttherebetween, and a current to flow from the current source 191 throughthe light emitting element 182 to the ground, thereby allowing the lightemitting element 182 to emit light.

On the other hand, suppose that a drive voltage is not applied to atleast either the first switching wiring 187 or the second switchingwiring 188. In this case, no voltage is applied to the gate portion ofthe current supply transistor 184 and thus no current flows through thelight emitting element 182, thereby causing no light emission.

In the embodiment shown in FIG. 35, a ground wiring 186 and a currentsupply wiring 189 are added to the arrangement shown in FIG. 34.

The embodiment shown in FIG. 36 is different from the arrangement shownin FIG. 35 in that the first switching wiring and the ground wiring areshared as a common wiring 192. In this arrangement, a ground potentialand a switching potential are alternately applied to the common wiring192 in a time division manner such that different potentials are appliedto adjacent common wirings.

FIG. 37 is a circuit connection diagram of a light emitting elementaccording to an embodiment of the present invention. In this embodiment,a switching transistor is also employed as the switching element and acurrent supply transistor is also employed as the current supplyelement, respectively.

The switching wirings are made up of the first switching wiring 187 andthe second switching wiring. 188. The drain portion 193 a of theswitching transistor 183 is connected to the second switching wiring188, while the gate portion 194 a is connected to the first switchingwiring 187, respectively. The source portion 195 a is connected to thegate portion 194 b of the current supply transistor 184 and one terminalof the voltage sustain capacitor 185. The other terminal of the voltagesustain capacitor 185 is connected to the ground 190. The drain portion193 b of the current supply transistor 184 is connected to the cathodeside of the light emitting element 182, while the source portion 195 bis connected to the ground 190. The anode portion of the light emittingelement 182 is connected to the current supply source 191.

In this arrangement, when a drive voltage is simultaneously applied tothe first switching wiring 187 and the second switching wiring 188, avoltage is provided to the source portion 195 a of the switchingtransistor 183 so as to cause electric charge to be accumulated in thevoltage sustain capacitor 185. This allows a stable potential to beapplied to the gate portion 194 b of the current supply transistor 184.This allows a current to flow from the current source 191 through thelight emitting element 182, and then from the drain portion 193 b of thecurrent supply transistor 184 through the source portion 195 b to theground 190. This allows the light emitting element 182 to emit light.

On the other hand, when a drive voltage is not applied to at least anyone of the first switching wiring 187 and the second switching wiring188, no voltage is applied to the gate portion of the current supplytransistor 184 and no current flows through the light emitting element182, thereby causing no light emission.

In the embodiment shown in FIG. 38, the ground wiring 186 and thecurrent supply wiring 189 are added to the arrangement shown in FIG. 37.

The embodiment shown in FIG. 39 is different from the arrangement shownin FIG. 38 in that the first switching wiring and the ground wiring areshared as the common wiring 192. In this arrangement, a ground potentialand a switching potential are alternately applied to the common wiring192 in a time division manner.

Now, explained below are design variations of how to arrange lightemitting elements, how to relate them to a substrate surface, how toconstruct their multilayer structure and the like, which are applicableto the present invention.

FIG. 40 is a schematic sectional view showing an exemplary arrangementof light emitting elements of a plurality of colors. In this structure,a first color light emitting element 40, a second color light emittingelement 41, and a third color light emitting element 42 are arranged onthe base assembly 1 alternately in that order. The first color lightemitting element 40, the second color light emitting element 41, and thethird color light emitting element 42 are typically selected from lightemitting elements which emit mainly blue light, green light, and redlight, respectively.

FIG. 41 is a schematic sectional view showing another exemplaryarrangement of light emitting elements. In this structure, at least partof a first color light emitting element 40, a second color lightemitting element 41, and a third color light emitting element 42 isembedded in the base assembly 1 and arranged in sequence. The firstcolor light emitting element 40, the second color light emitting element41, and the third color light emitting element 42 are typically selectedfrom light emitting elements which emit mainly blue light, green light,and red light, respectively.

FIG. 42 is a schematic sectional view showing another exemplaryarrangement of light emitting elements. In this structure, the firstcolor light emitting element 40, the second color light emitting element41, and the third color light emitting element are arranged on the baseassembly 1 alternately in that order, with a bank 52 being formedbetween the individual elements. The first color light emitting element40, the second color light emitting element 41, and the third colorlight emitting element are typically selected from light emittingelements which emit mainly blue light, green light, and red light,respectively.

FIG. 43 is a schematic sectional view showing an exemplary structure andarrangement of light emitting elements. In this structure, themultilayer structure of a lower electrode 43/a first color electrontransport layer 62/a first color light emitting layer 53, the multilayerstructure of the lower electrode 43/a second color electron transportlayer 63/a second color light emitting layer 54, and the multilayerstructure of the lower electrode 43/a third color electron transportlayer 64/a third color light emitting layer 55 are arranged on the baseassembly 1 alternately in that order, with the bank 52 being formedbetween the individual elements. Upon them, a hole injection layer 46and a transparent electrode layer 47 are formed across a plurality oflight emitting elements. The first, second, and third colors aretypically selected from light beams which are predominantly composed ofblue color, green color, and red color, respectively.

FIG. 44 is a schematic sectional view showing an exemplary structure andarrangement of light emitting elements. In this structure, themultilayer structure of the lower electrode 43/the first color electrontransport layer 62/the first color light emitting layer 53/a first colorhole injection layer 56, the multilayer structure of the lower electrode43/the second color electron transport layer 63/the second color lightemitting layer 54/a second color hole injection layer 57, and themultilayer structure of the lower electrode 43/the third color electrontransport layer 64/the third color light emitting layer 55/a third colorhole injection layer 58 are arranged on the base assembly 1 alternatelyin that order. Upon them, the transparent electrode layer 47 is formedacross a plurality of light emitting elements. The first, second, andthird colors are typically selected from light beams which arepredominantly composed of blue color, green color, and red color,respectively.

FIG. 45 is a schematic sectional view showing an exemplary structure andarrangement of light emitting elements. In this structure, themultilayer structure of the lower electrode 43/the first color electrontransport layer 62/the first color light emitting layer 53, themultilayer structure of the lower electrode 43/the second color electrontransport layer 63/the second color light emitting layer 54, and themultilayer structure of the lower electrode 43/the third color electrontransport layer 64/the third color light emitting layer 55 are arrangedon the base assembly 1 alternately in that order. Upon them, the holeinjection layer 46 and the transparent electrode layer 47 are formedacross a plurality of elements. The first, second, and third colors aretypically selected from light beams which are predominantly composed ofblue color, green color, and red color, respectively.

FIG. 46 is a schematic sectional view showing an exemplary structure andarrangement of light emitting elements. In this structure, themultilayer structures of the lower electrode 43/an electron transportlayer 44/a light emitting layer 45/the hole injection layer 46/thetransparent electrode layer 47 are spaced apart from one another on thebase assembly 1.

FIG. 47 is a schematic sectional view showing an exemplary structure andarrangement of light emitting elements. In this structure, themultilayer structure of the lower electrode 43/the electron transportlayer 44/the light emitting layer 45/the hole injection layer 46/thetransparent electrode layer 47 is formed in a recessed portion formed inthe base assembly 1.

Now, the structure of a light emitting element with a drive portion towhich the present invention is applied will be described morespecifically below.

FIG. 48 shows a light emitting element portion and a current supplyelement portion for the light emitting element. In this structure, abarrier layer 205 is formed on a substrate 1 a, on top of which a drainregion 193, a channel region 194, and a source region 195 of a thin filmtransistor (TFT) are formed as shown in the figure. On top of them,formed is a gate insulating film 198. On the gate insulating film andabove the channel region 194 of the TFT, formed is a gate electrode 206,on top of which formed is a first interlayer insulating film 199. In thegate insulating film 198 and the first interlayer insulating film 199,provided are openings for exposing part of the surfaces of the drainregion 193 and the source region 195 of the TFT. In these openings,there are formed a drain electrode 200 and a source electrode 201, whichare in contact with the drain region 193 and the source region 195,respectively. As shown, on top of them, a second interlayer insulatingfilm 202 is formed excluding on the region where the drain electrode 200is formed. Although not shown here, the source electrode 201 isconnected to a ground wiring, while the gate electrode 206 is connectedto the source electrode of a switching transistor. On the secondinterlayer insulating film 202, there is formed a lower electrode 203such that its one end is in contact with the drain electrode 200. On thetop thereof, a light emitting material layer 204 and a transparentelectrode 197 are sequentially formed. Employed as the light emittingmaterial layer 204 are a three-layer film made up of an electrontransport layer/a light emitting layer/a hole injection layer, atwo-layer film made up of a light emitting layer serving also as anelectron transport layer/a hole injection layer, or a single-layer filmmade up of a light emitting layer serving also as an electron transportlayer and a hole injection layer. Here, such a case was shown in whichthe light emitting material layer 204 and the transparent electrode 197are patterned in single light emitting elements; however, they may alsobe a large pattern that covers a plurality of elements.

FIG. 49 is a sectional view showing another exemplary light emittingelement with a drive portion to which the present invention is applied.In this example, the lower electrode 203 is connected to a ground wiringlocated outside the figure, with the transparent electrode 197 being incontact with the source electrode 201. In addition, although not shown,the drain electrode 200 is connected to a current supply wiring, whilethe gate electrode 206 is connected to a source electrode of a switchingtransistor.

FIG. 50 is a plan view showing the element having the sectionalstructure shown in FIG. 48, showing the peripheral region including itswiring portion. The first switching wiring (gate line) 187 is connectedto the gate portion 194 a of the switching transistor 183. The secondswitching wiring (data line) 188 is connected to the drain portion 193 aof the switching transistor 183.

The source portion 195 a of the switching transistor 183 is connected tothe gate portion 194 b of the current supply transistor 184 as well asto one terminal of the voltage sustain capacitor 185 (or to the lowerside of 185 in the figure) that is formed between it and the groundwiring 186. The other terminal of the voltage sustain capacitor 185 (orthe upper side of 185 in the figure) is connected to the ground wiring186.

The drain portion 193 b of the current supply transistor is connected tothe lower electrode 203. The source portion 195 b of the current supplytransistor 184 is connected to the ground wiring 186.

A light emitting material layer and a transparent electrode (both notshown) are formed on the lower electrode 203, with the transparentelectrode being connected to a current supply source (not shown). Thelight emitting layer and the transparent electrode formed thereon mayalso be formed on the entire surface to be shared by a plurality oflight emitting elements.

Typically, each member constituting the light emitting element and itsdrive portion may employ those shown in Table 1.

TABLE 1 Substrate Glass, Resin, Quartz, Ceramics, Metal Transparent ITO(Indium Tin Oxide), Mixture of In electrode layer Oxide and Zn OxideMetal electrode MgAg, Al, LiAl layer Electron transport QuinolinolAluminum complex (Alq₃), PBD, layer TAZ, END, Oxazole derivative (OXD),OXD- 7, Polyphenylene vinylene (PPV) Light emitting Material ofquinolinol aluminum complex layer, Light doped with red fluorescentpigment, emitting layer quinolinol aluminum complex, beryllium servingalso as a benzoquinolinol complex, zinc oxazole hole injection layercomplex, or a material containing a and/or an electron conjugatepolymeric organic compound transport layer precursor and at least onetype of fluorescent substance. For example, the precursor may bepolyphenylene vinylene or its derivative; the fluorescent pigment may berhodamine B, distilbiphenyl, coumarin, tetraphenylbutadiene quinacridon,and their derivatives Hole injection layer Triphenyl diamine derivative(TPD), porphin compound such as copper phthalocyanine, α-NPD Anodebuffer layer CuPc, polyaniline, polythiophene Protective layer Film ofAl oxide, Al nitride, Si oxide, or Si nitride, or film of their mixture,or their compound film Enhanced hygroscopic Ba oxide, Ca oxide layerSwitching element Transistor, diode, MM Current supply Transistorelement Wiring such as Silicide or polycide of high melting- switchingwiring point metal such as Al, Cu, Ta, Ru, and WSi

On the other hand, each element that constitutes the switchingtransistor or the current supply transistor can employ those listed inTable 2.

TABLE 2 Source-drain Silicide or polycide of high melting- electrode,gate point metal such as Al, Cu, Ta, Ru, and electrode WSi Gateinsulating Film of Al oxide, Al nitride, Si oxide, film, first or Sinitride, or film of their mixture, interlayer or their compound filminsulating film, second interlayer insulating film, barrier layer

On the other hand, an element used for sealing a light emitting elementcan employ those listed in Table 3.

TABLE 3 Adhesive UV-curable resin, thermosetting resin Sealing numberMetal, glass, resin Sealing glass Inert gas such as N₂, H₂, and Ar

Now, referring to FIGS. 51( a) to 53(l), described below is a method formanufacturing an organic EL device according to the present inventionthat was described with reference to FIG. 48 and FIG. 50.

First, as shown in FIG. 51( a), the substrate 1 a is prepared. Thesubstrate 1 a is typically made of non-alkali glass. As shown in FIG.51( b), on this substrate, the barrier layer 205 made of SiO₂ or thelike is formed by sputtering or by CVD (Chemical Vapor Deposition). Asshown in FIG. 51( c), silicon is deposited thereon by LP (Low pressure)CVD at about a growth temperature of 500° C. and irradiated with a laserbeam to form polycrystalline silicon, which is then patterned byphotolithography and by dry etching to form a polycrystalline siliconfilm 180. Then, as shown in FIG. 51( d), SiO₂ or the like is depositedby sputtering or by CVD to form the gate insulating film 198. Typically,the SiO₂ is deposited by remote plasma CVD. A conductive film, typicallyWSi, is deposited thereon by sputtering or by vapor deposition, and thenpatterned by photolithography and by ion milling to form the gateelectrode 206, as shown in FIG. 51( e).

Then, as shown in FIG. 52( f), boron or phosphorus is ion doped usingthe gate electrode 206 as a mask to form the drain region 193 and thesource region 195. The region under the gate electrode 206 which is notsubjected to the ion doping is the channel region 194. Heat treatment iscarried out typically at a temperature of about 550° C. in order toactivate the drain and source regions. Then, as shown in FIG. 52( g),SiO₂ is typically deposited by sputtering or by CVD to form the firstinterlayer insulating film 199. Subsequently, the first interlayerinsulating film 199 and the gate insulating film 198 are selectivelyremoved by photolithography and by dry etching to open a contact hole onthe source and drain regions. Then, as shown in FIG. 52( h), Al istypically deposited by sputtering to form the drain electrode 200 andthe source electrode 201, which are in contact with the drain and sourceregions, by photolithography and by dry etching. Then, as shown in FIG.52( i), on top thereof, SiO₂ is typically deposited by sputtering or byCVD to form the second interlayer insulating film 202, which is thenselectively removed by photolithography and by dry etching to form anopening on the drain electrode 200.

Then, as shown in FIG. 53( j), light metal or light metal alloy isdeposited by sputtering and then patterned to form the lower electrode203 that is in contact with the drain electrode 200. On top thereof, asshown in FIG. 53( k), the pattern of the light emitting material layer204 is formed. At this time, used is a vapor deposition method employinga metal mask or a formation technique employing an inkjet head On topthereof, as shown in FIG. 53( l), transparent conductive film isdeposited by sputtering, by CVD, or by spin-coating to form thetransparent electrode 197. Thereafter, the transparent conductive filmis patterned by photolithography.

Now, the embodiments of the present invention will be described in moredetail. For the embodiments, light emitting display devices wereprototyped using the light emitting elements having the structures orarrangements shown in FIG. 6( d), FIG. 18( a) or 18(c), FIG. 18( b),FIG. 27, FIG. 29, FIG. 30( a), FIG. 30( b), FIG. 35, FIG. 48, and FIG.50. A single unit element has a size of 30 μm×100 μm, with a displayportion having a size of 40 mm×40 mm.

To prototype these elements, a non-alkali glass substrate was employedas the base assembly, AlLi as the metal electrode layer, α-NPD as thehole injection layer, and Alq₃ as the light emitting layer serving alsoas an electron transport layer. Polyaniline was employed as the anodebuffer layer. The transparent electrode layer employed a mixture of Inoxide and Sn (In_(2-x)Sn_(x)O_(3-y)). The first switching wiring, thesecond switching wiring, and the ground line employed Al.

The indium tin oxide film was prepared using a In_(2-x)Sn_(x) target byreactive sputtering in an environment of Ar+O₂. At this time, the ratioof O₂ to Ar was varied to change the value of y in theIn_(2-x)Sn_(x)O_(3-y). To determine the value of y, theIn_(2-x)Sn_(x)O_(3-y) film which was prepared separately was analyzed bythe Rutherford backscattering spectrometry (RBS). Here, “x′” with an “′”added to the “x” in the In_(2-x)Sn_(x)O_(3-y) means that the value of xmay possibly be different between in the film and in the target (notanalyzed).

In the embodiment having the structure shown in FIG. 18( c), theenhanced hygroscopic layer employed a Ba oxide. The switching elementand the current supply element employed a transistor (TFT) The sourceelectrode and drain electrode of the transistor employed Al and the gateelectrode employed WSi, while the gate insulating film, the firstinterlayer insulating film, the second interlayer insulating film, andthe barrier layer employed a Si oxide. The light emitting element wassurrounded by a replaced nitrogen environment and then encapsulated in ametal cap.

Two types of light emitting display devices were fabricated, one havingan enhanced hygroscopic layer and the other not having it. A voltage of5V was applied to the anode portion made of a transparent electrode.Then, a voltage of 5V was applied to all the switching wirings (gatelines) and the second switching wirings (data lines) to measure, using aphotometer at room temperature, the period of time taken to reduce thelight emission from the elements by half.

Table 4 indicates the relationship between the value of y of theIn_(2-x)Sn_(x)O_(3-y) film and the light emission half time (measured inhours), for various types of In_(2-x)Sn_(x) targets employed. Table 4shows the cases in which the structures of FIG. 18( a) and FIG. 18( c)were used.

TABLE 4 FIG. 18a FIG. 18c y = 0.01 y = 0.03 y = 0.06 y = 0.1 y = 0.15 y= 0.2 y = 0.3 y = 0.06 x = 0.05 49 48 340 280 320 220 21 570 x = 0.1 5290 350 360 320 240 18 580 x = 0.2 47 45 360 330 340 250 17 460

With the value of x in the In_(2-x)Sn_(x) target taking any one of 0.05,0.1, or 0.2, it was found that the light emission half time was lessthan 100 hours for the values of y equal to or less than 0.03. In therange of y varying from 0.06 to 0.2, the half time was 220 hours ormore, while being as extremely short as 21 hours or less for the valueof y being 0.3.

This shows that the value of y lies within the range of 0.06 to 0.2 toensure the light emission sustain time. This is because theIn_(2-x)Sn_(x)O_(3-y) film somewhat deficient in oxygen has a bettermoisture absorption capability, thereby being able to absorb themoisture around the light emitting elements and provide an improvedemission lifetime.

Furthermore, the structure shown in FIG. 18( c) has a light emissionhalf time 1.5 times longer when compared with the light emittingelements fabricated using the In_(2-x)Sn_(x)O_(3-y) film that has beenprepared using the same value of y (y=0.06) The In_(2-x)Sn_(x)O_(3-y)film absorbs moisture around the light emitting elements and theenhanced hygroscopic layer further absorbs the moisture, thereby makingit possible to further reduce the amount of moisture around the lightemitting elements and thus provide a further improved emission lifetime.

1. An organic EL device having a light emitting element comprising: asubstrate; a first electrode; a second electrode of transparentconductive film; and a light emitting organic material layer formedbetween said first electrode and said second electrode, wherein saidtransparent conductive film is made of a metal oxide deficient in oxygenas compared with stoichiometric composition and is made of ITO having acomposition of In_(2-x)Sn_(x)O_(3-y)(where 0<x<1 and 0.05≦y≦0.2),wherein said first electrode is arranged between said second electrodeand said substrate, and an enhanced hygroscopic layer and/or aprotective layer are formed on said second electrode.
 2. The organic ELdevice according to claim 1, wherein said first electrode is made ofmetal.
 3. The organic EL device according to claim 1, wherein said firstelectrode is made of any one of MgAg, Al, and LiAl.
 4. The organic ELdevice according to claim 1, wherein said light emitting organicmaterial layer serves also as a hole injection layer and/or an electrontransport layer.
 5. The organic EL device according to claim 1, whereinan electron transport layer is inserted between said first electrode andsaid light emitting organic material layer.
 6. The organic EL deviceaccording to claim 1, wherein an anode buffer layer and/or a holeinjection layer is inserted between said second electrode and said lightemitting organic material layer.
 7. An organic EL device having a lightemitting element comprising: a first electrode; a second electrode oftransparent conductive film; and a light emitting organic material layerformed between said first electrode and said second electrode, whereinsaid transparent conductive film is made of a metal oxide deficient inoxygen as compared with stoichiometric composition and is made of ITOhaving a composition of In_(2-x)Sn_(x)O_(3-y)(where 0<x<0.3 and0.05≦y≦0.2), wherein said second electrode, of said first electrode andsaid second electrode, is formed on a substrate side, and a protectivelayer is formed on said first electrode, and wherein an enhancedhygroscopic layer is formed adjacent to said second electrode between asubstrate and said second electrode.
 8. The organic EL device accordingto claim 1, wherein said light emitting element is encapsulated in asealing member adhered onto said substrate.
 9. The organic EL deviceaccording to claim 8, wherein Na, H₂, or an inert gas is sealed in aspace encapsulated in said sealing material.